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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2012
6 *
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <linux/uaccess.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct {
55 char *string;
56 /*
57 * This assumes that all args are converted into longs
58 * on L/390 this is the case for all types of parameter
59 * except of floats, and long long (32 bit)
60 *
61 */
62 long args[0];
63} debug_sprintf_entry_t;
64
65/* internal function prototyes */
66
67static int debug_init(void);
68static ssize_t debug_output(struct file *file, char __user *user_buf,
69 size_t user_len, loff_t *offset);
70static ssize_t debug_input(struct file *file, const char __user *user_buf,
71 size_t user_len, loff_t *offset);
72static int debug_open(struct inode *inode, struct file *file);
73static int debug_close(struct inode *inode, struct file *file);
74static debug_info_t *debug_info_create(const char *name, int pages_per_area,
75 int nr_areas, int buf_size, umode_t mode);
76static void debug_info_get(debug_info_t *);
77static void debug_info_put(debug_info_t *);
78static int debug_prolog_level_fn(debug_info_t *id,
79 struct debug_view *view, char *out_buf);
80static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
81 struct file *file, const char __user *user_buf,
82 size_t user_buf_size, loff_t *offset);
83static int debug_prolog_pages_fn(debug_info_t *id,
84 struct debug_view *view, char *out_buf);
85static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
86 struct file *file, const char __user *user_buf,
87 size_t user_buf_size, loff_t *offset);
88static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
89 struct file *file, const char __user *user_buf,
90 size_t user_buf_size, loff_t *offset);
91static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
92 char *out_buf, const char *in_buf);
93static int debug_raw_format_fn(debug_info_t *id,
94 struct debug_view *view, char *out_buf,
95 const char *in_buf);
96static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
97 int area, debug_entry_t *entry, char *out_buf);
98
99static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
100 char *out_buf, debug_sprintf_entry_t *curr_event);
101
102/* globals */
103
104struct debug_view debug_raw_view = {
105 "raw",
106 NULL,
107 &debug_raw_header_fn,
108 &debug_raw_format_fn,
109 NULL,
110 NULL
111};
112EXPORT_SYMBOL(debug_raw_view);
113
114struct debug_view debug_hex_ascii_view = {
115 "hex_ascii",
116 NULL,
117 &debug_dflt_header_fn,
118 &debug_hex_ascii_format_fn,
119 NULL,
120 NULL
121};
122EXPORT_SYMBOL(debug_hex_ascii_view);
123
124static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131};
132
133static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140};
141
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t *)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158};
159EXPORT_SYMBOL(debug_sprintf_view);
160
161/* used by dump analysis tools to determine version of debug feature */
162static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164/* static globals */
165
166static debug_info_t *debug_area_first;
167static debug_info_t *debug_area_last;
168static DEFINE_MUTEX(debug_mutex);
169
170static int initialized;
171static int debug_critical;
172
173static const struct file_operations debug_file_ops = {
174 .owner = THIS_MODULE,
175 .read = debug_output,
176 .write = debug_input,
177 .open = debug_open,
178 .release = debug_close,
179 .llseek = no_llseek,
180};
181
182static struct dentry *debug_debugfs_root_entry;
183
184/* functions */
185
186/*
187 * debug_areas_alloc
188 * - Debug areas are implemented as a threedimensonal array:
189 * areas[areanumber][pagenumber][pageoffset]
190 */
191
192static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
193{
194 debug_entry_t ***areas;
195 int i, j;
196
197 areas = kmalloc_array(nr_areas, sizeof(debug_entry_t **), GFP_KERNEL);
198 if (!areas)
199 goto fail_malloc_areas;
200 for (i = 0; i < nr_areas; i++) {
201 areas[i] = kmalloc_array(pages_per_area,
202 sizeof(debug_entry_t *),
203 GFP_KERNEL);
204 if (!areas[i])
205 goto fail_malloc_areas2;
206 for (j = 0; j < pages_per_area; j++) {
207 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
208 if (!areas[i][j]) {
209 for (j--; j >= 0 ; j--)
210 kfree(areas[i][j]);
211 kfree(areas[i]);
212 goto fail_malloc_areas2;
213 }
214 }
215 }
216 return areas;
217
218fail_malloc_areas2:
219 for (i--; i >= 0; i--) {
220 for (j = 0; j < pages_per_area; j++)
221 kfree(areas[i][j]);
222 kfree(areas[i]);
223 }
224 kfree(areas);
225fail_malloc_areas:
226 return NULL;
227}
228
229/*
230 * debug_info_alloc
231 * - alloc new debug-info
232 */
233static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
234 int nr_areas, int buf_size, int level,
235 int mode)
236{
237 debug_info_t *rc;
238
239 /* alloc everything */
240 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
241 if (!rc)
242 goto fail_malloc_rc;
243 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
244 if (!rc->active_entries)
245 goto fail_malloc_active_entries;
246 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
247 if (!rc->active_pages)
248 goto fail_malloc_active_pages;
249 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
250 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
251 if (!rc->areas)
252 goto fail_malloc_areas;
253 } else {
254 rc->areas = NULL;
255 }
256
257 /* initialize members */
258 spin_lock_init(&rc->lock);
259 rc->pages_per_area = pages_per_area;
260 rc->nr_areas = nr_areas;
261 rc->active_area = 0;
262 rc->level = level;
263 rc->buf_size = buf_size;
264 rc->entry_size = sizeof(debug_entry_t) + buf_size;
265 strlcpy(rc->name, name, sizeof(rc->name));
266 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
267 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
268 refcount_set(&(rc->ref_count), 0);
269
270 return rc;
271
272fail_malloc_areas:
273 kfree(rc->active_pages);
274fail_malloc_active_pages:
275 kfree(rc->active_entries);
276fail_malloc_active_entries:
277 kfree(rc);
278fail_malloc_rc:
279 return NULL;
280}
281
282/*
283 * debug_areas_free
284 * - free all debug areas
285 */
286static void debug_areas_free(debug_info_t *db_info)
287{
288 int i, j;
289
290 if (!db_info->areas)
291 return;
292 for (i = 0; i < db_info->nr_areas; i++) {
293 for (j = 0; j < db_info->pages_per_area; j++)
294 kfree(db_info->areas[i][j]);
295 kfree(db_info->areas[i]);
296 }
297 kfree(db_info->areas);
298 db_info->areas = NULL;
299}
300
301/*
302 * debug_info_free
303 * - free memory debug-info
304 */
305static void debug_info_free(debug_info_t *db_info)
306{
307 debug_areas_free(db_info);
308 kfree(db_info->active_entries);
309 kfree(db_info->active_pages);
310 kfree(db_info);
311}
312
313/*
314 * debug_info_create
315 * - create new debug-info
316 */
317
318static debug_info_t *debug_info_create(const char *name, int pages_per_area,
319 int nr_areas, int buf_size, umode_t mode)
320{
321 debug_info_t *rc;
322
323 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
324 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
325 if (!rc)
326 goto out;
327
328 rc->mode = mode & ~S_IFMT;
329
330 /* create root directory */
331 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
332 debug_debugfs_root_entry);
333
334 /* append new element to linked list */
335 if (!debug_area_first) {
336 /* first element in list */
337 debug_area_first = rc;
338 rc->prev = NULL;
339 } else {
340 /* append element to end of list */
341 debug_area_last->next = rc;
342 rc->prev = debug_area_last;
343 }
344 debug_area_last = rc;
345 rc->next = NULL;
346
347 refcount_set(&rc->ref_count, 1);
348out:
349 return rc;
350}
351
352/*
353 * debug_info_copy
354 * - copy debug-info
355 */
356static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
357{
358 unsigned long flags;
359 debug_info_t *rc;
360 int i, j;
361
362 /* get a consistent copy of the debug areas */
363 do {
364 rc = debug_info_alloc(in->name, in->pages_per_area,
365 in->nr_areas, in->buf_size, in->level, mode);
366 spin_lock_irqsave(&in->lock, flags);
367 if (!rc)
368 goto out;
369 /* has something changed in the meantime ? */
370 if ((rc->pages_per_area == in->pages_per_area) &&
371 (rc->nr_areas == in->nr_areas)) {
372 break;
373 }
374 spin_unlock_irqrestore(&in->lock, flags);
375 debug_info_free(rc);
376 } while (1);
377
378 if (mode == NO_AREAS)
379 goto out;
380
381 for (i = 0; i < in->nr_areas; i++) {
382 for (j = 0; j < in->pages_per_area; j++)
383 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
384 }
385out:
386 spin_unlock_irqrestore(&in->lock, flags);
387 return rc;
388}
389
390/*
391 * debug_info_get
392 * - increments reference count for debug-info
393 */
394static void debug_info_get(debug_info_t *db_info)
395{
396 if (db_info)
397 refcount_inc(&db_info->ref_count);
398}
399
400/*
401 * debug_info_put:
402 * - decreases reference count for debug-info and frees it if necessary
403 */
404static void debug_info_put(debug_info_t *db_info)
405{
406 int i;
407
408 if (!db_info)
409 return;
410 if (refcount_dec_and_test(&db_info->ref_count)) {
411 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
412 if (!db_info->views[i])
413 continue;
414 debugfs_remove(db_info->debugfs_entries[i]);
415 }
416 debugfs_remove(db_info->debugfs_root_entry);
417 if (db_info == debug_area_first)
418 debug_area_first = db_info->next;
419 if (db_info == debug_area_last)
420 debug_area_last = db_info->prev;
421 if (db_info->prev)
422 db_info->prev->next = db_info->next;
423 if (db_info->next)
424 db_info->next->prev = db_info->prev;
425 debug_info_free(db_info);
426 }
427}
428
429/*
430 * debug_format_entry:
431 * - format one debug entry and return size of formated data
432 */
433static int debug_format_entry(file_private_info_t *p_info)
434{
435 debug_info_t *id_snap = p_info->debug_info_snap;
436 struct debug_view *view = p_info->view;
437 debug_entry_t *act_entry;
438 size_t len = 0;
439
440 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
441 /* print prolog */
442 if (view->prolog_proc)
443 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
444 goto out;
445 }
446 if (!id_snap->areas) /* this is true, if we have a prolog only view */
447 goto out; /* or if 'pages_per_area' is 0 */
448 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
449 [p_info->act_page] + p_info->act_entry);
450
451 if (act_entry->id.stck == 0LL)
452 goto out; /* empty entry */
453 if (view->header_proc)
454 len += view->header_proc(id_snap, view, p_info->act_area,
455 act_entry, p_info->temp_buf + len);
456 if (view->format_proc)
457 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
458 DEBUG_DATA(act_entry));
459out:
460 return len;
461}
462
463/*
464 * debug_next_entry:
465 * - goto next entry in p_info
466 */
467static inline int debug_next_entry(file_private_info_t *p_info)
468{
469 debug_info_t *id;
470
471 id = p_info->debug_info_snap;
472 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
473 p_info->act_entry = 0;
474 p_info->act_page = 0;
475 goto out;
476 }
477 if (!id->areas)
478 return 1;
479 p_info->act_entry += id->entry_size;
480 /* switch to next page, if we reached the end of the page */
481 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
482 /* next page */
483 p_info->act_entry = 0;
484 p_info->act_page += 1;
485 if ((p_info->act_page % id->pages_per_area) == 0) {
486 /* next area */
487 p_info->act_area++;
488 p_info->act_page = 0;
489 }
490 if (p_info->act_area >= id->nr_areas)
491 return 1;
492 }
493out:
494 return 0;
495}
496
497/*
498 * debug_output:
499 * - called for user read()
500 * - copies formated debug entries to the user buffer
501 */
502static ssize_t debug_output(struct file *file, /* file descriptor */
503 char __user *user_buf, /* user buffer */
504 size_t len, /* length of buffer */
505 loff_t *offset) /* offset in the file */
506{
507 size_t count = 0;
508 size_t entry_offset;
509 file_private_info_t *p_info;
510
511 p_info = (file_private_info_t *) file->private_data;
512 if (*offset != p_info->offset)
513 return -EPIPE;
514 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
515 return 0;
516 entry_offset = p_info->act_entry_offset;
517 while (count < len) {
518 int formatted_line_residue;
519 int formatted_line_size;
520 int user_buf_residue;
521 size_t copy_size;
522
523 formatted_line_size = debug_format_entry(p_info);
524 formatted_line_residue = formatted_line_size - entry_offset;
525 user_buf_residue = len-count;
526 copy_size = min(user_buf_residue, formatted_line_residue);
527 if (copy_size) {
528 if (copy_to_user(user_buf + count, p_info->temp_buf
529 + entry_offset, copy_size))
530 return -EFAULT;
531 count += copy_size;
532 entry_offset += copy_size;
533 }
534 if (copy_size == formatted_line_residue) {
535 entry_offset = 0;
536 if (debug_next_entry(p_info))
537 goto out;
538 }
539 }
540out:
541 p_info->offset = *offset + count;
542 p_info->act_entry_offset = entry_offset;
543 *offset = p_info->offset;
544 return count;
545}
546
547/*
548 * debug_input:
549 * - called for user write()
550 * - calls input function of view
551 */
552static ssize_t debug_input(struct file *file, const char __user *user_buf,
553 size_t length, loff_t *offset)
554{
555 file_private_info_t *p_info;
556 int rc = 0;
557
558 mutex_lock(&debug_mutex);
559 p_info = ((file_private_info_t *) file->private_data);
560 if (p_info->view->input_proc) {
561 rc = p_info->view->input_proc(p_info->debug_info_org,
562 p_info->view, file, user_buf,
563 length, offset);
564 } else {
565 rc = -EPERM;
566 }
567 mutex_unlock(&debug_mutex);
568 return rc; /* number of input characters */
569}
570
571/*
572 * debug_open:
573 * - called for user open()
574 * - copies formated output to private_data area of the file
575 * handle
576 */
577static int debug_open(struct inode *inode, struct file *file)
578{
579 debug_info_t *debug_info, *debug_info_snapshot;
580 file_private_info_t *p_info;
581 int i, rc = 0;
582
583 mutex_lock(&debug_mutex);
584 debug_info = file_inode(file)->i_private;
585 /* find debug view */
586 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
587 if (!debug_info->views[i])
588 continue;
589 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
590 goto found; /* found view ! */
591 }
592 /* no entry found */
593 rc = -EINVAL;
594 goto out;
595
596found:
597
598 /* Make snapshot of current debug areas to get it consistent. */
599 /* To copy all the areas is only needed, if we have a view which */
600 /* formats the debug areas. */
601
602 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
603 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
604 else
605 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
606
607 if (!debug_info_snapshot) {
608 rc = -ENOMEM;
609 goto out;
610 }
611 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
612 if (!p_info) {
613 debug_info_free(debug_info_snapshot);
614 rc = -ENOMEM;
615 goto out;
616 }
617 p_info->offset = 0;
618 p_info->debug_info_snap = debug_info_snapshot;
619 p_info->debug_info_org = debug_info;
620 p_info->view = debug_info->views[i];
621 p_info->act_area = 0;
622 p_info->act_page = 0;
623 p_info->act_entry = DEBUG_PROLOG_ENTRY;
624 p_info->act_entry_offset = 0;
625 file->private_data = p_info;
626 debug_info_get(debug_info);
627 nonseekable_open(inode, file);
628out:
629 mutex_unlock(&debug_mutex);
630 return rc;
631}
632
633/*
634 * debug_close:
635 * - called for user close()
636 * - deletes private_data area of the file handle
637 */
638static int debug_close(struct inode *inode, struct file *file)
639{
640 file_private_info_t *p_info;
641
642 p_info = (file_private_info_t *) file->private_data;
643 if (p_info->debug_info_snap)
644 debug_info_free(p_info->debug_info_snap);
645 debug_info_put(p_info->debug_info_org);
646 kfree(file->private_data);
647 return 0; /* success */
648}
649
650/**
651 * debug_register_mode() - creates and initializes debug area.
652 *
653 * @name: Name of debug log (e.g. used for debugfs entry)
654 * @pages_per_area: Number of pages, which will be allocated per area
655 * @nr_areas: Number of debug areas
656 * @buf_size: Size of data area in each debug entry
657 * @mode: File mode for debugfs files. E.g. S_IRWXUGO
658 * @uid: User ID for debugfs files. Currently only 0 is supported.
659 * @gid: Group ID for debugfs files. Currently only 0 is supported.
660 *
661 * Return:
662 * - Handle for generated debug area
663 * - %NULL if register failed
664 *
665 * Allocates memory for a debug log.
666 * Must not be called within an interrupt handler.
667 */
668debug_info_t *debug_register_mode(const char *name, int pages_per_area,
669 int nr_areas, int buf_size, umode_t mode,
670 uid_t uid, gid_t gid)
671{
672 debug_info_t *rc = NULL;
673
674 /* Since debugfs currently does not support uid/gid other than root, */
675 /* we do not allow gid/uid != 0 until we get support for that. */
676 if ((uid != 0) || (gid != 0))
677 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
678 BUG_ON(!initialized);
679 mutex_lock(&debug_mutex);
680
681 /* create new debug_info */
682 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
683 if (!rc)
684 goto out;
685 debug_register_view(rc, &debug_level_view);
686 debug_register_view(rc, &debug_flush_view);
687 debug_register_view(rc, &debug_pages_view);
688out:
689 if (!rc)
690 pr_err("Registering debug feature %s failed\n", name);
691 mutex_unlock(&debug_mutex);
692 return rc;
693}
694EXPORT_SYMBOL(debug_register_mode);
695
696/**
697 * debug_register() - creates and initializes debug area with default file mode.
698 *
699 * @name: Name of debug log (e.g. used for debugfs entry)
700 * @pages_per_area: Number of pages, which will be allocated per area
701 * @nr_areas: Number of debug areas
702 * @buf_size: Size of data area in each debug entry
703 *
704 * Return:
705 * - Handle for generated debug area
706 * - %NULL if register failed
707 *
708 * Allocates memory for a debug log.
709 * The debugfs file mode access permissions are read and write for user.
710 * Must not be called within an interrupt handler.
711 */
712debug_info_t *debug_register(const char *name, int pages_per_area,
713 int nr_areas, int buf_size)
714{
715 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
716 S_IRUSR | S_IWUSR, 0, 0);
717}
718EXPORT_SYMBOL(debug_register);
719
720/**
721 * debug_unregister() - give back debug area.
722 *
723 * @id: handle for debug log
724 *
725 * Return:
726 * none
727 */
728void debug_unregister(debug_info_t *id)
729{
730 if (!id)
731 return;
732 mutex_lock(&debug_mutex);
733 debug_info_put(id);
734 mutex_unlock(&debug_mutex);
735}
736EXPORT_SYMBOL(debug_unregister);
737
738/*
739 * debug_set_size:
740 * - set area size (number of pages) and number of areas
741 */
742static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
743{
744 debug_entry_t ***new_areas;
745 unsigned long flags;
746 int rc = 0;
747
748 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
749 return -EINVAL;
750 if (pages_per_area > 0) {
751 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
752 if (!new_areas) {
753 pr_info("Allocating memory for %i pages failed\n",
754 pages_per_area);
755 rc = -ENOMEM;
756 goto out;
757 }
758 } else {
759 new_areas = NULL;
760 }
761 spin_lock_irqsave(&id->lock, flags);
762 debug_areas_free(id);
763 id->areas = new_areas;
764 id->nr_areas = nr_areas;
765 id->pages_per_area = pages_per_area;
766 id->active_area = 0;
767 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
768 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
769 spin_unlock_irqrestore(&id->lock, flags);
770 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
771out:
772 return rc;
773}
774
775/**
776 * debug_set_level() - Sets new actual debug level if new_level is valid.
777 *
778 * @id: handle for debug log
779 * @new_level: new debug level
780 *
781 * Return:
782 * none
783 */
784void debug_set_level(debug_info_t *id, int new_level)
785{
786 unsigned long flags;
787
788 if (!id)
789 return;
790 spin_lock_irqsave(&id->lock, flags);
791 if (new_level == DEBUG_OFF_LEVEL) {
792 id->level = DEBUG_OFF_LEVEL;
793 pr_info("%s: switched off\n", id->name);
794 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
795 pr_info("%s: level %i is out of range (%i - %i)\n",
796 id->name, new_level, 0, DEBUG_MAX_LEVEL);
797 } else {
798 id->level = new_level;
799 }
800 spin_unlock_irqrestore(&id->lock, flags);
801}
802EXPORT_SYMBOL(debug_set_level);
803
804/*
805 * proceed_active_entry:
806 * - set active entry to next in the ring buffer
807 */
808static inline void proceed_active_entry(debug_info_t *id)
809{
810 if ((id->active_entries[id->active_area] += id->entry_size)
811 > (PAGE_SIZE - id->entry_size)) {
812 id->active_entries[id->active_area] = 0;
813 id->active_pages[id->active_area] =
814 (id->active_pages[id->active_area] + 1) %
815 id->pages_per_area;
816 }
817}
818
819/*
820 * proceed_active_area:
821 * - set active area to next in the ring buffer
822 */
823static inline void proceed_active_area(debug_info_t *id)
824{
825 id->active_area++;
826 id->active_area = id->active_area % id->nr_areas;
827}
828
829/*
830 * get_active_entry:
831 */
832static inline debug_entry_t *get_active_entry(debug_info_t *id)
833{
834 return (debug_entry_t *) (((char *) id->areas[id->active_area]
835 [id->active_pages[id->active_area]]) +
836 id->active_entries[id->active_area]);
837}
838
839/*
840 * debug_finish_entry:
841 * - set timestamp, caller address, cpu number etc.
842 */
843
844static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
845 int level, int exception)
846{
847 active->id.stck = get_tod_clock_fast() -
848 *(unsigned long long *) &tod_clock_base[1];
849 active->id.fields.cpuid = smp_processor_id();
850 active->caller = __builtin_return_address(0);
851 active->id.fields.exception = exception;
852 active->id.fields.level = level;
853 proceed_active_entry(id);
854 if (exception)
855 proceed_active_area(id);
856}
857
858static int debug_stoppable = 1;
859static int debug_active = 1;
860
861#define CTL_S390DBF_STOPPABLE 5678
862#define CTL_S390DBF_ACTIVE 5679
863
864/*
865 * proc handler for the running debug_active sysctl
866 * always allow read, allow write only if debug_stoppable is set or
867 * if debug_active is already off
868 */
869static int s390dbf_procactive(struct ctl_table *table, int write,
870 void __user *buffer, size_t *lenp, loff_t *ppos)
871{
872 if (!write || debug_stoppable || !debug_active)
873 return proc_dointvec(table, write, buffer, lenp, ppos);
874 else
875 return 0;
876}
877
878static struct ctl_table s390dbf_table[] = {
879 {
880 .procname = "debug_stoppable",
881 .data = &debug_stoppable,
882 .maxlen = sizeof(int),
883 .mode = S_IRUGO | S_IWUSR,
884 .proc_handler = proc_dointvec,
885 },
886 {
887 .procname = "debug_active",
888 .data = &debug_active,
889 .maxlen = sizeof(int),
890 .mode = S_IRUGO | S_IWUSR,
891 .proc_handler = s390dbf_procactive,
892 },
893 { }
894};
895
896static struct ctl_table s390dbf_dir_table[] = {
897 {
898 .procname = "s390dbf",
899 .maxlen = 0,
900 .mode = S_IRUGO | S_IXUGO,
901 .child = s390dbf_table,
902 },
903 { }
904};
905
906static struct ctl_table_header *s390dbf_sysctl_header;
907
908/**
909 * debug_stop_all() - stops the debug feature if stopping is allowed.
910 *
911 * Return:
912 * - none
913 *
914 * Currently used in case of a kernel oops.
915 */
916void debug_stop_all(void)
917{
918 if (debug_stoppable)
919 debug_active = 0;
920}
921EXPORT_SYMBOL(debug_stop_all);
922
923/**
924 * debug_set_critical() - event/exception functions try lock instead of spin.
925 *
926 * Return:
927 * - none
928 *
929 * Currently used in case of stopping all CPUs but the current one.
930 * Once in this state, functions to write a debug entry for an
931 * event or exception no longer spin on the debug area lock,
932 * but only try to get it and fail if they do not get the lock.
933 */
934void debug_set_critical(void)
935{
936 debug_critical = 1;
937}
938
939/*
940 * debug_event_common:
941 * - write debug entry with given size
942 */
943debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
944 int len)
945{
946 debug_entry_t *active;
947 unsigned long flags;
948
949 if (!debug_active || !id->areas)
950 return NULL;
951 if (debug_critical) {
952 if (!spin_trylock_irqsave(&id->lock, flags))
953 return NULL;
954 } else {
955 spin_lock_irqsave(&id->lock, flags);
956 }
957 do {
958 active = get_active_entry(id);
959 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
960 if (len < id->buf_size)
961 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
962 debug_finish_entry(id, active, level, 0);
963 len -= id->buf_size;
964 buf += id->buf_size;
965 } while (len > 0);
966
967 spin_unlock_irqrestore(&id->lock, flags);
968 return active;
969}
970EXPORT_SYMBOL(debug_event_common);
971
972/*
973 * debug_exception_common:
974 * - write debug entry with given size and switch to next debug area
975 */
976debug_entry_t *debug_exception_common(debug_info_t *id, int level,
977 const void *buf, int len)
978{
979 debug_entry_t *active;
980 unsigned long flags;
981
982 if (!debug_active || !id->areas)
983 return NULL;
984 if (debug_critical) {
985 if (!spin_trylock_irqsave(&id->lock, flags))
986 return NULL;
987 } else {
988 spin_lock_irqsave(&id->lock, flags);
989 }
990 do {
991 active = get_active_entry(id);
992 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
993 if (len < id->buf_size)
994 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
995 debug_finish_entry(id, active, level, len <= id->buf_size);
996 len -= id->buf_size;
997 buf += id->buf_size;
998 } while (len > 0);
999
1000 spin_unlock_irqrestore(&id->lock, flags);
1001 return active;
1002}
1003EXPORT_SYMBOL(debug_exception_common);
1004
1005/*
1006 * counts arguments in format string for sprintf view
1007 */
1008static inline int debug_count_numargs(char *string)
1009{
1010 int numargs = 0;
1011
1012 while (*string) {
1013 if (*string++ == '%')
1014 numargs++;
1015 }
1016 return numargs;
1017}
1018
1019/*
1020 * debug_sprintf_event:
1021 */
1022debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
1023{
1024 debug_sprintf_entry_t *curr_event;
1025 debug_entry_t *active;
1026 unsigned long flags;
1027 int numargs, idx;
1028 va_list ap;
1029
1030 if (!debug_active || !id->areas)
1031 return NULL;
1032 numargs = debug_count_numargs(string);
1033
1034 if (debug_critical) {
1035 if (!spin_trylock_irqsave(&id->lock, flags))
1036 return NULL;
1037 } else {
1038 spin_lock_irqsave(&id->lock, flags);
1039 }
1040 active = get_active_entry(id);
1041 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
1042 va_start(ap, string);
1043 curr_event->string = string;
1044 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1045 curr_event->args[idx] = va_arg(ap, long);
1046 va_end(ap);
1047 debug_finish_entry(id, active, level, 0);
1048 spin_unlock_irqrestore(&id->lock, flags);
1049
1050 return active;
1051}
1052EXPORT_SYMBOL(__debug_sprintf_event);
1053
1054/*
1055 * debug_sprintf_exception:
1056 */
1057debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1058{
1059 debug_sprintf_entry_t *curr_event;
1060 debug_entry_t *active;
1061 unsigned long flags;
1062 int numargs, idx;
1063 va_list ap;
1064
1065 if (!debug_active || !id->areas)
1066 return NULL;
1067
1068 numargs = debug_count_numargs(string);
1069
1070 if (debug_critical) {
1071 if (!spin_trylock_irqsave(&id->lock, flags))
1072 return NULL;
1073 } else {
1074 spin_lock_irqsave(&id->lock, flags);
1075 }
1076 active = get_active_entry(id);
1077 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1078 va_start(ap, string);
1079 curr_event->string = string;
1080 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1081 curr_event->args[idx] = va_arg(ap, long);
1082 va_end(ap);
1083 debug_finish_entry(id, active, level, 1);
1084 spin_unlock_irqrestore(&id->lock, flags);
1085
1086 return active;
1087}
1088EXPORT_SYMBOL(__debug_sprintf_exception);
1089
1090/**
1091 * debug_register_view() - registers new debug view and creates debugfs
1092 * dir entry
1093 *
1094 * @id: handle for debug log
1095 * @view: pointer to debug view struct
1096 *
1097 * Return:
1098 * - 0 : ok
1099 * - < 0: Error
1100 */
1101int debug_register_view(debug_info_t *id, struct debug_view *view)
1102{
1103 unsigned long flags;
1104 struct dentry *pde;
1105 umode_t mode;
1106 int rc = 0;
1107 int i;
1108
1109 if (!id)
1110 goto out;
1111 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1112 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1113 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1114 if (!view->input_proc)
1115 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1116 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1117 id, &debug_file_ops);
1118 spin_lock_irqsave(&id->lock, flags);
1119 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1120 if (!id->views[i])
1121 break;
1122 }
1123 if (i == DEBUG_MAX_VIEWS) {
1124 pr_err("Registering view %s/%s would exceed the maximum "
1125 "number of views %i\n", id->name, view->name, i);
1126 rc = -1;
1127 } else {
1128 id->views[i] = view;
1129 id->debugfs_entries[i] = pde;
1130 }
1131 spin_unlock_irqrestore(&id->lock, flags);
1132 if (rc)
1133 debugfs_remove(pde);
1134out:
1135 return rc;
1136}
1137EXPORT_SYMBOL(debug_register_view);
1138
1139/**
1140 * debug_unregister_view() - unregisters debug view and removes debugfs
1141 * dir entry
1142 *
1143 * @id: handle for debug log
1144 * @view: pointer to debug view struct
1145 *
1146 * Return:
1147 * - 0 : ok
1148 * - < 0: Error
1149 */
1150int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1151{
1152 struct dentry *dentry = NULL;
1153 unsigned long flags;
1154 int i, rc = 0;
1155
1156 if (!id)
1157 goto out;
1158 spin_lock_irqsave(&id->lock, flags);
1159 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1160 if (id->views[i] == view)
1161 break;
1162 }
1163 if (i == DEBUG_MAX_VIEWS) {
1164 rc = -1;
1165 } else {
1166 dentry = id->debugfs_entries[i];
1167 id->views[i] = NULL;
1168 id->debugfs_entries[i] = NULL;
1169 }
1170 spin_unlock_irqrestore(&id->lock, flags);
1171 debugfs_remove(dentry);
1172out:
1173 return rc;
1174}
1175EXPORT_SYMBOL(debug_unregister_view);
1176
1177static inline char *debug_get_user_string(const char __user *user_buf,
1178 size_t user_len)
1179{
1180 char *buffer;
1181
1182 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1183 if (!buffer)
1184 return ERR_PTR(-ENOMEM);
1185 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1186 kfree(buffer);
1187 return ERR_PTR(-EFAULT);
1188 }
1189 /* got the string, now strip linefeed. */
1190 if (buffer[user_len - 1] == '\n')
1191 buffer[user_len - 1] = 0;
1192 else
1193 buffer[user_len] = 0;
1194 return buffer;
1195}
1196
1197static inline int debug_get_uint(char *buf)
1198{
1199 int rc;
1200
1201 buf = skip_spaces(buf);
1202 rc = simple_strtoul(buf, &buf, 10);
1203 if (*buf)
1204 rc = -EINVAL;
1205 return rc;
1206}
1207
1208/*
1209 * functions for debug-views
1210 ***********************************
1211*/
1212
1213/*
1214 * prints out actual debug level
1215 */
1216
1217static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1218 char *out_buf)
1219{
1220 return sprintf(out_buf, "%i\n", id->pages_per_area);
1221}
1222
1223/*
1224 * reads new size (number of pages per debug area)
1225 */
1226
1227static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1228 struct file *file, const char __user *user_buf,
1229 size_t user_len, loff_t *offset)
1230{
1231 int rc, new_pages;
1232 char *str;
1233
1234 if (user_len > 0x10000)
1235 user_len = 0x10000;
1236 if (*offset != 0) {
1237 rc = -EPIPE;
1238 goto out;
1239 }
1240 str = debug_get_user_string(user_buf, user_len);
1241 if (IS_ERR(str)) {
1242 rc = PTR_ERR(str);
1243 goto out;
1244 }
1245 new_pages = debug_get_uint(str);
1246 if (new_pages < 0) {
1247 rc = -EINVAL;
1248 goto free_str;
1249 }
1250 rc = debug_set_size(id, id->nr_areas, new_pages);
1251 if (rc != 0) {
1252 rc = -EINVAL;
1253 goto free_str;
1254 }
1255 rc = user_len;
1256free_str:
1257 kfree(str);
1258out:
1259 *offset += user_len;
1260 return rc; /* number of input characters */
1261}
1262
1263/*
1264 * prints out actual debug level
1265 */
1266static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1267 char *out_buf)
1268{
1269 int rc = 0;
1270
1271 if (id->level == DEBUG_OFF_LEVEL)
1272 rc = sprintf(out_buf, "-\n");
1273 else
1274 rc = sprintf(out_buf, "%i\n", id->level);
1275 return rc;
1276}
1277
1278/*
1279 * reads new debug level
1280 */
1281static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1282 struct file *file, const char __user *user_buf,
1283 size_t user_len, loff_t *offset)
1284{
1285 int rc, new_level;
1286 char *str;
1287
1288 if (user_len > 0x10000)
1289 user_len = 0x10000;
1290 if (*offset != 0) {
1291 rc = -EPIPE;
1292 goto out;
1293 }
1294 str = debug_get_user_string(user_buf, user_len);
1295 if (IS_ERR(str)) {
1296 rc = PTR_ERR(str);
1297 goto out;
1298 }
1299 if (str[0] == '-') {
1300 debug_set_level(id, DEBUG_OFF_LEVEL);
1301 rc = user_len;
1302 goto free_str;
1303 } else {
1304 new_level = debug_get_uint(str);
1305 }
1306 if (new_level < 0) {
1307 pr_warn("%s is not a valid level for a debug feature\n", str);
1308 rc = -EINVAL;
1309 } else {
1310 debug_set_level(id, new_level);
1311 rc = user_len;
1312 }
1313free_str:
1314 kfree(str);
1315out:
1316 *offset += user_len;
1317 return rc; /* number of input characters */
1318}
1319
1320/*
1321 * flushes debug areas
1322 */
1323static void debug_flush(debug_info_t *id, int area)
1324{
1325 unsigned long flags;
1326 int i, j;
1327
1328 if (!id || !id->areas)
1329 return;
1330 spin_lock_irqsave(&id->lock, flags);
1331 if (area == DEBUG_FLUSH_ALL) {
1332 id->active_area = 0;
1333 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1334 for (i = 0; i < id->nr_areas; i++) {
1335 id->active_pages[i] = 0;
1336 for (j = 0; j < id->pages_per_area; j++)
1337 memset(id->areas[i][j], 0, PAGE_SIZE);
1338 }
1339 } else if (area >= 0 && area < id->nr_areas) {
1340 id->active_entries[area] = 0;
1341 id->active_pages[area] = 0;
1342 for (i = 0; i < id->pages_per_area; i++)
1343 memset(id->areas[area][i], 0, PAGE_SIZE);
1344 }
1345 spin_unlock_irqrestore(&id->lock, flags);
1346}
1347
1348/*
1349 * view function: flushes debug areas
1350 */
1351static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1352 struct file *file, const char __user *user_buf,
1353 size_t user_len, loff_t *offset)
1354{
1355 char input_buf[1];
1356 int rc = user_len;
1357
1358 if (user_len > 0x10000)
1359 user_len = 0x10000;
1360 if (*offset != 0) {
1361 rc = -EPIPE;
1362 goto out;
1363 }
1364 if (copy_from_user(input_buf, user_buf, 1)) {
1365 rc = -EFAULT;
1366 goto out;
1367 }
1368 if (input_buf[0] == '-') {
1369 debug_flush(id, DEBUG_FLUSH_ALL);
1370 goto out;
1371 }
1372 if (isdigit(input_buf[0])) {
1373 int area = ((int) input_buf[0] - (int) '0');
1374
1375 debug_flush(id, area);
1376 goto out;
1377 }
1378
1379 pr_info("Flushing debug data failed because %c is not a valid "
1380 "area\n", input_buf[0]);
1381
1382out:
1383 *offset += user_len;
1384 return rc; /* number of input characters */
1385}
1386
1387/*
1388 * prints debug header in raw format
1389 */
1390static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1391 int area, debug_entry_t *entry, char *out_buf)
1392{
1393 int rc;
1394
1395 rc = sizeof(debug_entry_t);
1396 memcpy(out_buf, entry, sizeof(debug_entry_t));
1397 return rc;
1398}
1399
1400/*
1401 * prints debug data in raw format
1402 */
1403static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1404 char *out_buf, const char *in_buf)
1405{
1406 int rc;
1407
1408 rc = id->buf_size;
1409 memcpy(out_buf, in_buf, id->buf_size);
1410 return rc;
1411}
1412
1413/*
1414 * prints debug data in hex/ascii format
1415 */
1416static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1417 char *out_buf, const char *in_buf)
1418{
1419 int i, rc = 0;
1420
1421 for (i = 0; i < id->buf_size; i++)
1422 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1423 rc += sprintf(out_buf + rc, "| ");
1424 for (i = 0; i < id->buf_size; i++) {
1425 unsigned char c = in_buf[i];
1426
1427 if (isascii(c) && isprint(c))
1428 rc += sprintf(out_buf + rc, "%c", c);
1429 else
1430 rc += sprintf(out_buf + rc, ".");
1431 }
1432 rc += sprintf(out_buf + rc, "\n");
1433 return rc;
1434}
1435
1436/*
1437 * prints header for debug entry
1438 */
1439int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1440 int area, debug_entry_t *entry, char *out_buf)
1441{
1442 unsigned long base, sec, usec;
1443 unsigned long caller;
1444 unsigned int level;
1445 char *except_str;
1446 int rc = 0;
1447
1448 level = entry->id.fields.level;
1449 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1450 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1451 usec = do_div(sec, USEC_PER_SEC);
1452
1453 if (entry->id.fields.exception)
1454 except_str = "*";
1455 else
1456 except_str = "-";
1457 caller = (unsigned long) entry->caller;
1458 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1459 area, sec, usec, level, except_str,
1460 entry->id.fields.cpuid, (void *)caller);
1461 return rc;
1462}
1463EXPORT_SYMBOL(debug_dflt_header_fn);
1464
1465/*
1466 * prints debug data sprintf-formated:
1467 * debug_sprinf_event/exception calls must be used together with this view
1468 */
1469
1470#define DEBUG_SPRINTF_MAX_ARGS 10
1471
1472static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1473 char *out_buf, debug_sprintf_entry_t *curr_event)
1474{
1475 int num_longs, num_used_args = 0, i, rc = 0;
1476 int index[DEBUG_SPRINTF_MAX_ARGS];
1477
1478 /* count of longs fit into one entry */
1479 num_longs = id->buf_size / sizeof(long);
1480
1481 if (num_longs < 1)
1482 goto out; /* bufsize of entry too small */
1483 if (num_longs == 1) {
1484 /* no args, we use only the string */
1485 strcpy(out_buf, curr_event->string);
1486 rc = strlen(curr_event->string);
1487 goto out;
1488 }
1489
1490 /* number of arguments used for sprintf (without the format string) */
1491 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1492
1493 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1494
1495 for (i = 0; i < num_used_args; i++)
1496 index[i] = i;
1497
1498 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1499 curr_event->args[index[1]], curr_event->args[index[2]],
1500 curr_event->args[index[3]], curr_event->args[index[4]],
1501 curr_event->args[index[5]], curr_event->args[index[6]],
1502 curr_event->args[index[7]], curr_event->args[index[8]],
1503 curr_event->args[index[9]]);
1504out:
1505 return rc;
1506}
1507
1508/*
1509 * debug_init:
1510 * - is called exactly once to initialize the debug feature
1511 */
1512static int __init debug_init(void)
1513{
1514 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1515 mutex_lock(&debug_mutex);
1516 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1517 initialized = 1;
1518 mutex_unlock(&debug_mutex);
1519 return 0;
1520}
1521postcore_initcall(debug_init);
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * S/390 debug facility
4 *
5 * Copyright IBM Corp. 1999, 2012
6 *
7 * Author(s): Michael Holzheu (holzheu@de.ibm.com),
8 * Holger Smolinski (Holger.Smolinski@de.ibm.com)
9 *
10 * Bugreports to: <Linux390@de.ibm.com>
11 */
12
13#define KMSG_COMPONENT "s390dbf"
14#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
15
16#include <linux/stddef.h>
17#include <linux/kernel.h>
18#include <linux/errno.h>
19#include <linux/slab.h>
20#include <linux/ctype.h>
21#include <linux/string.h>
22#include <linux/sysctl.h>
23#include <linux/uaccess.h>
24#include <linux/export.h>
25#include <linux/init.h>
26#include <linux/fs.h>
27#include <linux/debugfs.h>
28
29#include <asm/debug.h>
30
31#define DEBUG_PROLOG_ENTRY -1
32
33#define ALL_AREAS 0 /* copy all debug areas */
34#define NO_AREAS 1 /* copy no debug areas */
35
36/* typedefs */
37
38typedef struct file_private_info {
39 loff_t offset; /* offset of last read in file */
40 int act_area; /* number of last formated area */
41 int act_page; /* act page in given area */
42 int act_entry; /* last formated entry (offset */
43 /* relative to beginning of last */
44 /* formated page) */
45 size_t act_entry_offset; /* up to this offset we copied */
46 /* in last read the last formated */
47 /* entry to userland */
48 char temp_buf[2048]; /* buffer for output */
49 debug_info_t *debug_info_org; /* original debug information */
50 debug_info_t *debug_info_snap; /* snapshot of debug information */
51 struct debug_view *view; /* used view of debug info */
52} file_private_info_t;
53
54typedef struct {
55 char *string;
56 /*
57 * This assumes that all args are converted into longs
58 * on L/390 this is the case for all types of parameter
59 * except of floats, and long long (32 bit)
60 *
61 */
62 long args[0];
63} debug_sprintf_entry_t;
64
65/* internal function prototyes */
66
67static int debug_init(void);
68static ssize_t debug_output(struct file *file, char __user *user_buf,
69 size_t user_len, loff_t *offset);
70static ssize_t debug_input(struct file *file, const char __user *user_buf,
71 size_t user_len, loff_t *offset);
72static int debug_open(struct inode *inode, struct file *file);
73static int debug_close(struct inode *inode, struct file *file);
74static debug_info_t *debug_info_create(const char *name, int pages_per_area,
75 int nr_areas, int buf_size, umode_t mode);
76static void debug_info_get(debug_info_t *);
77static void debug_info_put(debug_info_t *);
78static int debug_prolog_level_fn(debug_info_t *id,
79 struct debug_view *view, char *out_buf);
80static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
81 struct file *file, const char __user *user_buf,
82 size_t user_buf_size, loff_t *offset);
83static int debug_prolog_pages_fn(debug_info_t *id,
84 struct debug_view *view, char *out_buf);
85static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
86 struct file *file, const char __user *user_buf,
87 size_t user_buf_size, loff_t *offset);
88static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
89 struct file *file, const char __user *user_buf,
90 size_t user_buf_size, loff_t *offset);
91static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
92 char *out_buf, const char *in_buf);
93static int debug_raw_format_fn(debug_info_t *id,
94 struct debug_view *view, char *out_buf,
95 const char *in_buf);
96static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
97 int area, debug_entry_t *entry, char *out_buf);
98
99static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
100 char *out_buf, debug_sprintf_entry_t *curr_event);
101
102/* globals */
103
104struct debug_view debug_raw_view = {
105 "raw",
106 NULL,
107 &debug_raw_header_fn,
108 &debug_raw_format_fn,
109 NULL,
110 NULL
111};
112EXPORT_SYMBOL(debug_raw_view);
113
114struct debug_view debug_hex_ascii_view = {
115 "hex_ascii",
116 NULL,
117 &debug_dflt_header_fn,
118 &debug_hex_ascii_format_fn,
119 NULL,
120 NULL
121};
122EXPORT_SYMBOL(debug_hex_ascii_view);
123
124static struct debug_view debug_level_view = {
125 "level",
126 &debug_prolog_level_fn,
127 NULL,
128 NULL,
129 &debug_input_level_fn,
130 NULL
131};
132
133static struct debug_view debug_pages_view = {
134 "pages",
135 &debug_prolog_pages_fn,
136 NULL,
137 NULL,
138 &debug_input_pages_fn,
139 NULL
140};
141
142static struct debug_view debug_flush_view = {
143 "flush",
144 NULL,
145 NULL,
146 NULL,
147 &debug_input_flush_fn,
148 NULL
149};
150
151struct debug_view debug_sprintf_view = {
152 "sprintf",
153 NULL,
154 &debug_dflt_header_fn,
155 (debug_format_proc_t *)&debug_sprintf_format_fn,
156 NULL,
157 NULL
158};
159EXPORT_SYMBOL(debug_sprintf_view);
160
161/* used by dump analysis tools to determine version of debug feature */
162static unsigned int __used debug_feature_version = __DEBUG_FEATURE_VERSION;
163
164/* static globals */
165
166static debug_info_t *debug_area_first;
167static debug_info_t *debug_area_last;
168static DEFINE_MUTEX(debug_mutex);
169
170static int initialized;
171static int debug_critical;
172
173static const struct file_operations debug_file_ops = {
174 .owner = THIS_MODULE,
175 .read = debug_output,
176 .write = debug_input,
177 .open = debug_open,
178 .release = debug_close,
179 .llseek = no_llseek,
180};
181
182static struct dentry *debug_debugfs_root_entry;
183
184/* functions */
185
186/*
187 * debug_areas_alloc
188 * - Debug areas are implemented as a threedimensonal array:
189 * areas[areanumber][pagenumber][pageoffset]
190 */
191
192static debug_entry_t ***debug_areas_alloc(int pages_per_area, int nr_areas)
193{
194 debug_entry_t ***areas;
195 int i, j;
196
197 areas = kmalloc(nr_areas * sizeof(debug_entry_t **), GFP_KERNEL);
198 if (!areas)
199 goto fail_malloc_areas;
200 for (i = 0; i < nr_areas; i++) {
201 areas[i] = kmalloc(pages_per_area * sizeof(debug_entry_t *), GFP_KERNEL);
202 if (!areas[i])
203 goto fail_malloc_areas2;
204 for (j = 0; j < pages_per_area; j++) {
205 areas[i][j] = kzalloc(PAGE_SIZE, GFP_KERNEL);
206 if (!areas[i][j]) {
207 for (j--; j >= 0 ; j--)
208 kfree(areas[i][j]);
209 kfree(areas[i]);
210 goto fail_malloc_areas2;
211 }
212 }
213 }
214 return areas;
215
216fail_malloc_areas2:
217 for (i--; i >= 0; i--) {
218 for (j = 0; j < pages_per_area; j++)
219 kfree(areas[i][j]);
220 kfree(areas[i]);
221 }
222 kfree(areas);
223fail_malloc_areas:
224 return NULL;
225}
226
227/*
228 * debug_info_alloc
229 * - alloc new debug-info
230 */
231static debug_info_t *debug_info_alloc(const char *name, int pages_per_area,
232 int nr_areas, int buf_size, int level,
233 int mode)
234{
235 debug_info_t *rc;
236
237 /* alloc everything */
238 rc = kmalloc(sizeof(debug_info_t), GFP_KERNEL);
239 if (!rc)
240 goto fail_malloc_rc;
241 rc->active_entries = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
242 if (!rc->active_entries)
243 goto fail_malloc_active_entries;
244 rc->active_pages = kcalloc(nr_areas, sizeof(int), GFP_KERNEL);
245 if (!rc->active_pages)
246 goto fail_malloc_active_pages;
247 if ((mode == ALL_AREAS) && (pages_per_area != 0)) {
248 rc->areas = debug_areas_alloc(pages_per_area, nr_areas);
249 if (!rc->areas)
250 goto fail_malloc_areas;
251 } else {
252 rc->areas = NULL;
253 }
254
255 /* initialize members */
256 spin_lock_init(&rc->lock);
257 rc->pages_per_area = pages_per_area;
258 rc->nr_areas = nr_areas;
259 rc->active_area = 0;
260 rc->level = level;
261 rc->buf_size = buf_size;
262 rc->entry_size = sizeof(debug_entry_t) + buf_size;
263 strlcpy(rc->name, name, sizeof(rc->name));
264 memset(rc->views, 0, DEBUG_MAX_VIEWS * sizeof(struct debug_view *));
265 memset(rc->debugfs_entries, 0, DEBUG_MAX_VIEWS * sizeof(struct dentry *));
266 refcount_set(&(rc->ref_count), 0);
267
268 return rc;
269
270fail_malloc_areas:
271 kfree(rc->active_pages);
272fail_malloc_active_pages:
273 kfree(rc->active_entries);
274fail_malloc_active_entries:
275 kfree(rc);
276fail_malloc_rc:
277 return NULL;
278}
279
280/*
281 * debug_areas_free
282 * - free all debug areas
283 */
284static void debug_areas_free(debug_info_t *db_info)
285{
286 int i, j;
287
288 if (!db_info->areas)
289 return;
290 for (i = 0; i < db_info->nr_areas; i++) {
291 for (j = 0; j < db_info->pages_per_area; j++)
292 kfree(db_info->areas[i][j]);
293 kfree(db_info->areas[i]);
294 }
295 kfree(db_info->areas);
296 db_info->areas = NULL;
297}
298
299/*
300 * debug_info_free
301 * - free memory debug-info
302 */
303static void debug_info_free(debug_info_t *db_info)
304{
305 debug_areas_free(db_info);
306 kfree(db_info->active_entries);
307 kfree(db_info->active_pages);
308 kfree(db_info);
309}
310
311/*
312 * debug_info_create
313 * - create new debug-info
314 */
315
316static debug_info_t *debug_info_create(const char *name, int pages_per_area,
317 int nr_areas, int buf_size, umode_t mode)
318{
319 debug_info_t *rc;
320
321 rc = debug_info_alloc(name, pages_per_area, nr_areas, buf_size,
322 DEBUG_DEFAULT_LEVEL, ALL_AREAS);
323 if (!rc)
324 goto out;
325
326 rc->mode = mode & ~S_IFMT;
327
328 /* create root directory */
329 rc->debugfs_root_entry = debugfs_create_dir(rc->name,
330 debug_debugfs_root_entry);
331
332 /* append new element to linked list */
333 if (!debug_area_first) {
334 /* first element in list */
335 debug_area_first = rc;
336 rc->prev = NULL;
337 } else {
338 /* append element to end of list */
339 debug_area_last->next = rc;
340 rc->prev = debug_area_last;
341 }
342 debug_area_last = rc;
343 rc->next = NULL;
344
345 refcount_set(&rc->ref_count, 1);
346out:
347 return rc;
348}
349
350/*
351 * debug_info_copy
352 * - copy debug-info
353 */
354static debug_info_t *debug_info_copy(debug_info_t *in, int mode)
355{
356 unsigned long flags;
357 debug_info_t *rc;
358 int i, j;
359
360 /* get a consistent copy of the debug areas */
361 do {
362 rc = debug_info_alloc(in->name, in->pages_per_area,
363 in->nr_areas, in->buf_size, in->level, mode);
364 spin_lock_irqsave(&in->lock, flags);
365 if (!rc)
366 goto out;
367 /* has something changed in the meantime ? */
368 if ((rc->pages_per_area == in->pages_per_area) &&
369 (rc->nr_areas == in->nr_areas)) {
370 break;
371 }
372 spin_unlock_irqrestore(&in->lock, flags);
373 debug_info_free(rc);
374 } while (1);
375
376 if (mode == NO_AREAS)
377 goto out;
378
379 for (i = 0; i < in->nr_areas; i++) {
380 for (j = 0; j < in->pages_per_area; j++)
381 memcpy(rc->areas[i][j], in->areas[i][j], PAGE_SIZE);
382 }
383out:
384 spin_unlock_irqrestore(&in->lock, flags);
385 return rc;
386}
387
388/*
389 * debug_info_get
390 * - increments reference count for debug-info
391 */
392static void debug_info_get(debug_info_t *db_info)
393{
394 if (db_info)
395 refcount_inc(&db_info->ref_count);
396}
397
398/*
399 * debug_info_put:
400 * - decreases reference count for debug-info and frees it if necessary
401 */
402static void debug_info_put(debug_info_t *db_info)
403{
404 int i;
405
406 if (!db_info)
407 return;
408 if (refcount_dec_and_test(&db_info->ref_count)) {
409 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
410 if (!db_info->views[i])
411 continue;
412 debugfs_remove(db_info->debugfs_entries[i]);
413 }
414 debugfs_remove(db_info->debugfs_root_entry);
415 if (db_info == debug_area_first)
416 debug_area_first = db_info->next;
417 if (db_info == debug_area_last)
418 debug_area_last = db_info->prev;
419 if (db_info->prev)
420 db_info->prev->next = db_info->next;
421 if (db_info->next)
422 db_info->next->prev = db_info->prev;
423 debug_info_free(db_info);
424 }
425}
426
427/*
428 * debug_format_entry:
429 * - format one debug entry and return size of formated data
430 */
431static int debug_format_entry(file_private_info_t *p_info)
432{
433 debug_info_t *id_snap = p_info->debug_info_snap;
434 struct debug_view *view = p_info->view;
435 debug_entry_t *act_entry;
436 size_t len = 0;
437
438 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
439 /* print prolog */
440 if (view->prolog_proc)
441 len += view->prolog_proc(id_snap, view, p_info->temp_buf);
442 goto out;
443 }
444 if (!id_snap->areas) /* this is true, if we have a prolog only view */
445 goto out; /* or if 'pages_per_area' is 0 */
446 act_entry = (debug_entry_t *) ((char *)id_snap->areas[p_info->act_area]
447 [p_info->act_page] + p_info->act_entry);
448
449 if (act_entry->id.stck == 0LL)
450 goto out; /* empty entry */
451 if (view->header_proc)
452 len += view->header_proc(id_snap, view, p_info->act_area,
453 act_entry, p_info->temp_buf + len);
454 if (view->format_proc)
455 len += view->format_proc(id_snap, view, p_info->temp_buf + len,
456 DEBUG_DATA(act_entry));
457out:
458 return len;
459}
460
461/*
462 * debug_next_entry:
463 * - goto next entry in p_info
464 */
465static inline int debug_next_entry(file_private_info_t *p_info)
466{
467 debug_info_t *id;
468
469 id = p_info->debug_info_snap;
470 if (p_info->act_entry == DEBUG_PROLOG_ENTRY) {
471 p_info->act_entry = 0;
472 p_info->act_page = 0;
473 goto out;
474 }
475 if (!id->areas)
476 return 1;
477 p_info->act_entry += id->entry_size;
478 /* switch to next page, if we reached the end of the page */
479 if (p_info->act_entry > (PAGE_SIZE - id->entry_size)) {
480 /* next page */
481 p_info->act_entry = 0;
482 p_info->act_page += 1;
483 if ((p_info->act_page % id->pages_per_area) == 0) {
484 /* next area */
485 p_info->act_area++;
486 p_info->act_page = 0;
487 }
488 if (p_info->act_area >= id->nr_areas)
489 return 1;
490 }
491out:
492 return 0;
493}
494
495/*
496 * debug_output:
497 * - called for user read()
498 * - copies formated debug entries to the user buffer
499 */
500static ssize_t debug_output(struct file *file, /* file descriptor */
501 char __user *user_buf, /* user buffer */
502 size_t len, /* length of buffer */
503 loff_t *offset) /* offset in the file */
504{
505 size_t count = 0;
506 size_t entry_offset;
507 file_private_info_t *p_info;
508
509 p_info = (file_private_info_t *) file->private_data;
510 if (*offset != p_info->offset)
511 return -EPIPE;
512 if (p_info->act_area >= p_info->debug_info_snap->nr_areas)
513 return 0;
514 entry_offset = p_info->act_entry_offset;
515 while (count < len) {
516 int formatted_line_residue;
517 int formatted_line_size;
518 int user_buf_residue;
519 size_t copy_size;
520
521 formatted_line_size = debug_format_entry(p_info);
522 formatted_line_residue = formatted_line_size - entry_offset;
523 user_buf_residue = len-count;
524 copy_size = min(user_buf_residue, formatted_line_residue);
525 if (copy_size) {
526 if (copy_to_user(user_buf + count, p_info->temp_buf
527 + entry_offset, copy_size))
528 return -EFAULT;
529 count += copy_size;
530 entry_offset += copy_size;
531 }
532 if (copy_size == formatted_line_residue) {
533 entry_offset = 0;
534 if (debug_next_entry(p_info))
535 goto out;
536 }
537 }
538out:
539 p_info->offset = *offset + count;
540 p_info->act_entry_offset = entry_offset;
541 *offset = p_info->offset;
542 return count;
543}
544
545/*
546 * debug_input:
547 * - called for user write()
548 * - calls input function of view
549 */
550static ssize_t debug_input(struct file *file, const char __user *user_buf,
551 size_t length, loff_t *offset)
552{
553 file_private_info_t *p_info;
554 int rc = 0;
555
556 mutex_lock(&debug_mutex);
557 p_info = ((file_private_info_t *) file->private_data);
558 if (p_info->view->input_proc) {
559 rc = p_info->view->input_proc(p_info->debug_info_org,
560 p_info->view, file, user_buf,
561 length, offset);
562 } else {
563 rc = -EPERM;
564 }
565 mutex_unlock(&debug_mutex);
566 return rc; /* number of input characters */
567}
568
569/*
570 * debug_open:
571 * - called for user open()
572 * - copies formated output to private_data area of the file
573 * handle
574 */
575static int debug_open(struct inode *inode, struct file *file)
576{
577 debug_info_t *debug_info, *debug_info_snapshot;
578 file_private_info_t *p_info;
579 int i, rc = 0;
580
581 mutex_lock(&debug_mutex);
582 debug_info = file_inode(file)->i_private;
583 /* find debug view */
584 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
585 if (!debug_info->views[i])
586 continue;
587 else if (debug_info->debugfs_entries[i] == file->f_path.dentry)
588 goto found; /* found view ! */
589 }
590 /* no entry found */
591 rc = -EINVAL;
592 goto out;
593
594found:
595
596 /* Make snapshot of current debug areas to get it consistent. */
597 /* To copy all the areas is only needed, if we have a view which */
598 /* formats the debug areas. */
599
600 if (!debug_info->views[i]->format_proc && !debug_info->views[i]->header_proc)
601 debug_info_snapshot = debug_info_copy(debug_info, NO_AREAS);
602 else
603 debug_info_snapshot = debug_info_copy(debug_info, ALL_AREAS);
604
605 if (!debug_info_snapshot) {
606 rc = -ENOMEM;
607 goto out;
608 }
609 p_info = kmalloc(sizeof(file_private_info_t), GFP_KERNEL);
610 if (!p_info) {
611 debug_info_free(debug_info_snapshot);
612 rc = -ENOMEM;
613 goto out;
614 }
615 p_info->offset = 0;
616 p_info->debug_info_snap = debug_info_snapshot;
617 p_info->debug_info_org = debug_info;
618 p_info->view = debug_info->views[i];
619 p_info->act_area = 0;
620 p_info->act_page = 0;
621 p_info->act_entry = DEBUG_PROLOG_ENTRY;
622 p_info->act_entry_offset = 0;
623 file->private_data = p_info;
624 debug_info_get(debug_info);
625 nonseekable_open(inode, file);
626out:
627 mutex_unlock(&debug_mutex);
628 return rc;
629}
630
631/*
632 * debug_close:
633 * - called for user close()
634 * - deletes private_data area of the file handle
635 */
636static int debug_close(struct inode *inode, struct file *file)
637{
638 file_private_info_t *p_info;
639
640 p_info = (file_private_info_t *) file->private_data;
641 if (p_info->debug_info_snap)
642 debug_info_free(p_info->debug_info_snap);
643 debug_info_put(p_info->debug_info_org);
644 kfree(file->private_data);
645 return 0; /* success */
646}
647
648/*
649 * debug_register_mode:
650 * - Creates and initializes debug area for the caller
651 * The mode parameter allows to specify access rights for the s390dbf files
652 * - Returns handle for debug area
653 */
654debug_info_t *debug_register_mode(const char *name, int pages_per_area,
655 int nr_areas, int buf_size, umode_t mode,
656 uid_t uid, gid_t gid)
657{
658 debug_info_t *rc = NULL;
659
660 /* Since debugfs currently does not support uid/gid other than root, */
661 /* we do not allow gid/uid != 0 until we get support for that. */
662 if ((uid != 0) || (gid != 0))
663 pr_warn("Root becomes the owner of all s390dbf files in sysfs\n");
664 BUG_ON(!initialized);
665 mutex_lock(&debug_mutex);
666
667 /* create new debug_info */
668 rc = debug_info_create(name, pages_per_area, nr_areas, buf_size, mode);
669 if (!rc)
670 goto out;
671 debug_register_view(rc, &debug_level_view);
672 debug_register_view(rc, &debug_flush_view);
673 debug_register_view(rc, &debug_pages_view);
674out:
675 if (!rc)
676 pr_err("Registering debug feature %s failed\n", name);
677 mutex_unlock(&debug_mutex);
678 return rc;
679}
680EXPORT_SYMBOL(debug_register_mode);
681
682/*
683 * debug_register:
684 * - creates and initializes debug area for the caller
685 * - returns handle for debug area
686 */
687debug_info_t *debug_register(const char *name, int pages_per_area,
688 int nr_areas, int buf_size)
689{
690 return debug_register_mode(name, pages_per_area, nr_areas, buf_size,
691 S_IRUSR | S_IWUSR, 0, 0);
692}
693EXPORT_SYMBOL(debug_register);
694
695/*
696 * debug_unregister:
697 * - give back debug area
698 */
699void debug_unregister(debug_info_t *id)
700{
701 if (!id)
702 return;
703 mutex_lock(&debug_mutex);
704 debug_info_put(id);
705 mutex_unlock(&debug_mutex);
706}
707EXPORT_SYMBOL(debug_unregister);
708
709/*
710 * debug_set_size:
711 * - set area size (number of pages) and number of areas
712 */
713static int debug_set_size(debug_info_t *id, int nr_areas, int pages_per_area)
714{
715 debug_entry_t ***new_areas;
716 unsigned long flags;
717 int rc = 0;
718
719 if (!id || (nr_areas <= 0) || (pages_per_area < 0))
720 return -EINVAL;
721 if (pages_per_area > 0) {
722 new_areas = debug_areas_alloc(pages_per_area, nr_areas);
723 if (!new_areas) {
724 pr_info("Allocating memory for %i pages failed\n",
725 pages_per_area);
726 rc = -ENOMEM;
727 goto out;
728 }
729 } else {
730 new_areas = NULL;
731 }
732 spin_lock_irqsave(&id->lock, flags);
733 debug_areas_free(id);
734 id->areas = new_areas;
735 id->nr_areas = nr_areas;
736 id->pages_per_area = pages_per_area;
737 id->active_area = 0;
738 memset(id->active_entries, 0, sizeof(int)*id->nr_areas);
739 memset(id->active_pages, 0, sizeof(int)*id->nr_areas);
740 spin_unlock_irqrestore(&id->lock, flags);
741 pr_info("%s: set new size (%i pages)\n", id->name, pages_per_area);
742out:
743 return rc;
744}
745
746/*
747 * debug_set_level:
748 * - set actual debug level
749 */
750void debug_set_level(debug_info_t *id, int new_level)
751{
752 unsigned long flags;
753
754 if (!id)
755 return;
756 spin_lock_irqsave(&id->lock, flags);
757 if (new_level == DEBUG_OFF_LEVEL) {
758 id->level = DEBUG_OFF_LEVEL;
759 pr_info("%s: switched off\n", id->name);
760 } else if ((new_level > DEBUG_MAX_LEVEL) || (new_level < 0)) {
761 pr_info("%s: level %i is out of range (%i - %i)\n",
762 id->name, new_level, 0, DEBUG_MAX_LEVEL);
763 } else {
764 id->level = new_level;
765 }
766 spin_unlock_irqrestore(&id->lock, flags);
767}
768EXPORT_SYMBOL(debug_set_level);
769
770/*
771 * proceed_active_entry:
772 * - set active entry to next in the ring buffer
773 */
774static inline void proceed_active_entry(debug_info_t *id)
775{
776 if ((id->active_entries[id->active_area] += id->entry_size)
777 > (PAGE_SIZE - id->entry_size)) {
778 id->active_entries[id->active_area] = 0;
779 id->active_pages[id->active_area] =
780 (id->active_pages[id->active_area] + 1) %
781 id->pages_per_area;
782 }
783}
784
785/*
786 * proceed_active_area:
787 * - set active area to next in the ring buffer
788 */
789static inline void proceed_active_area(debug_info_t *id)
790{
791 id->active_area++;
792 id->active_area = id->active_area % id->nr_areas;
793}
794
795/*
796 * get_active_entry:
797 */
798static inline debug_entry_t *get_active_entry(debug_info_t *id)
799{
800 return (debug_entry_t *) (((char *) id->areas[id->active_area]
801 [id->active_pages[id->active_area]]) +
802 id->active_entries[id->active_area]);
803}
804
805/*
806 * debug_finish_entry:
807 * - set timestamp, caller address, cpu number etc.
808 */
809
810static inline void debug_finish_entry(debug_info_t *id, debug_entry_t *active,
811 int level, int exception)
812{
813 active->id.stck = get_tod_clock_fast() -
814 *(unsigned long long *) &tod_clock_base[1];
815 active->id.fields.cpuid = smp_processor_id();
816 active->caller = __builtin_return_address(0);
817 active->id.fields.exception = exception;
818 active->id.fields.level = level;
819 proceed_active_entry(id);
820 if (exception)
821 proceed_active_area(id);
822}
823
824static int debug_stoppable = 1;
825static int debug_active = 1;
826
827#define CTL_S390DBF_STOPPABLE 5678
828#define CTL_S390DBF_ACTIVE 5679
829
830/*
831 * proc handler for the running debug_active sysctl
832 * always allow read, allow write only if debug_stoppable is set or
833 * if debug_active is already off
834 */
835static int s390dbf_procactive(struct ctl_table *table, int write,
836 void __user *buffer, size_t *lenp, loff_t *ppos)
837{
838 if (!write || debug_stoppable || !debug_active)
839 return proc_dointvec(table, write, buffer, lenp, ppos);
840 else
841 return 0;
842}
843
844static struct ctl_table s390dbf_table[] = {
845 {
846 .procname = "debug_stoppable",
847 .data = &debug_stoppable,
848 .maxlen = sizeof(int),
849 .mode = S_IRUGO | S_IWUSR,
850 .proc_handler = proc_dointvec,
851 },
852 {
853 .procname = "debug_active",
854 .data = &debug_active,
855 .maxlen = sizeof(int),
856 .mode = S_IRUGO | S_IWUSR,
857 .proc_handler = s390dbf_procactive,
858 },
859 { }
860};
861
862static struct ctl_table s390dbf_dir_table[] = {
863 {
864 .procname = "s390dbf",
865 .maxlen = 0,
866 .mode = S_IRUGO | S_IXUGO,
867 .child = s390dbf_table,
868 },
869 { }
870};
871
872static struct ctl_table_header *s390dbf_sysctl_header;
873
874void debug_stop_all(void)
875{
876 if (debug_stoppable)
877 debug_active = 0;
878}
879EXPORT_SYMBOL(debug_stop_all);
880
881void debug_set_critical(void)
882{
883 debug_critical = 1;
884}
885
886/*
887 * debug_event_common:
888 * - write debug entry with given size
889 */
890debug_entry_t *debug_event_common(debug_info_t *id, int level, const void *buf,
891 int len)
892{
893 debug_entry_t *active;
894 unsigned long flags;
895
896 if (!debug_active || !id->areas)
897 return NULL;
898 if (debug_critical) {
899 if (!spin_trylock_irqsave(&id->lock, flags))
900 return NULL;
901 } else {
902 spin_lock_irqsave(&id->lock, flags);
903 }
904 do {
905 active = get_active_entry(id);
906 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
907 if (len < id->buf_size)
908 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
909 debug_finish_entry(id, active, level, 0);
910 len -= id->buf_size;
911 buf += id->buf_size;
912 } while (len > 0);
913
914 spin_unlock_irqrestore(&id->lock, flags);
915 return active;
916}
917EXPORT_SYMBOL(debug_event_common);
918
919/*
920 * debug_exception_common:
921 * - write debug entry with given size and switch to next debug area
922 */
923debug_entry_t *debug_exception_common(debug_info_t *id, int level,
924 const void *buf, int len)
925{
926 debug_entry_t *active;
927 unsigned long flags;
928
929 if (!debug_active || !id->areas)
930 return NULL;
931 if (debug_critical) {
932 if (!spin_trylock_irqsave(&id->lock, flags))
933 return NULL;
934 } else {
935 spin_lock_irqsave(&id->lock, flags);
936 }
937 do {
938 active = get_active_entry(id);
939 memcpy(DEBUG_DATA(active), buf, min(len, id->buf_size));
940 if (len < id->buf_size)
941 memset((DEBUG_DATA(active)) + len, 0, id->buf_size - len);
942 debug_finish_entry(id, active, level, len <= id->buf_size);
943 len -= id->buf_size;
944 buf += id->buf_size;
945 } while (len > 0);
946
947 spin_unlock_irqrestore(&id->lock, flags);
948 return active;
949}
950EXPORT_SYMBOL(debug_exception_common);
951
952/*
953 * counts arguments in format string for sprintf view
954 */
955static inline int debug_count_numargs(char *string)
956{
957 int numargs = 0;
958
959 while (*string) {
960 if (*string++ == '%')
961 numargs++;
962 }
963 return numargs;
964}
965
966/*
967 * debug_sprintf_event:
968 */
969debug_entry_t *__debug_sprintf_event(debug_info_t *id, int level, char *string, ...)
970{
971 debug_sprintf_entry_t *curr_event;
972 debug_entry_t *active;
973 unsigned long flags;
974 int numargs, idx;
975 va_list ap;
976
977 if (!debug_active || !id->areas)
978 return NULL;
979 numargs = debug_count_numargs(string);
980
981 if (debug_critical) {
982 if (!spin_trylock_irqsave(&id->lock, flags))
983 return NULL;
984 } else {
985 spin_lock_irqsave(&id->lock, flags);
986 }
987 active = get_active_entry(id);
988 curr_event = (debug_sprintf_entry_t *) DEBUG_DATA(active);
989 va_start(ap, string);
990 curr_event->string = string;
991 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
992 curr_event->args[idx] = va_arg(ap, long);
993 va_end(ap);
994 debug_finish_entry(id, active, level, 0);
995 spin_unlock_irqrestore(&id->lock, flags);
996
997 return active;
998}
999EXPORT_SYMBOL(__debug_sprintf_event);
1000
1001/*
1002 * debug_sprintf_exception:
1003 */
1004debug_entry_t *__debug_sprintf_exception(debug_info_t *id, int level, char *string, ...)
1005{
1006 debug_sprintf_entry_t *curr_event;
1007 debug_entry_t *active;
1008 unsigned long flags;
1009 int numargs, idx;
1010 va_list ap;
1011
1012 if (!debug_active || !id->areas)
1013 return NULL;
1014
1015 numargs = debug_count_numargs(string);
1016
1017 if (debug_critical) {
1018 if (!spin_trylock_irqsave(&id->lock, flags))
1019 return NULL;
1020 } else {
1021 spin_lock_irqsave(&id->lock, flags);
1022 }
1023 active = get_active_entry(id);
1024 curr_event = (debug_sprintf_entry_t *)DEBUG_DATA(active);
1025 va_start(ap, string);
1026 curr_event->string = string;
1027 for (idx = 0; idx < min(numargs, (int)(id->buf_size / sizeof(long)) - 1); idx++)
1028 curr_event->args[idx] = va_arg(ap, long);
1029 va_end(ap);
1030 debug_finish_entry(id, active, level, 1);
1031 spin_unlock_irqrestore(&id->lock, flags);
1032
1033 return active;
1034}
1035EXPORT_SYMBOL(__debug_sprintf_exception);
1036
1037/*
1038 * debug_register_view:
1039 */
1040int debug_register_view(debug_info_t *id, struct debug_view *view)
1041{
1042 unsigned long flags;
1043 struct dentry *pde;
1044 umode_t mode;
1045 int rc = 0;
1046 int i;
1047
1048 if (!id)
1049 goto out;
1050 mode = (id->mode | S_IFREG) & ~S_IXUGO;
1051 if (!(view->prolog_proc || view->format_proc || view->header_proc))
1052 mode &= ~(S_IRUSR | S_IRGRP | S_IROTH);
1053 if (!view->input_proc)
1054 mode &= ~(S_IWUSR | S_IWGRP | S_IWOTH);
1055 pde = debugfs_create_file(view->name, mode, id->debugfs_root_entry,
1056 id, &debug_file_ops);
1057 if (!pde) {
1058 pr_err("Registering view %s/%s failed due to out of "
1059 "memory\n", id->name, view->name);
1060 rc = -1;
1061 goto out;
1062 }
1063 spin_lock_irqsave(&id->lock, flags);
1064 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1065 if (!id->views[i])
1066 break;
1067 }
1068 if (i == DEBUG_MAX_VIEWS) {
1069 pr_err("Registering view %s/%s would exceed the maximum "
1070 "number of views %i\n", id->name, view->name, i);
1071 rc = -1;
1072 } else {
1073 id->views[i] = view;
1074 id->debugfs_entries[i] = pde;
1075 }
1076 spin_unlock_irqrestore(&id->lock, flags);
1077 if (rc)
1078 debugfs_remove(pde);
1079out:
1080 return rc;
1081}
1082EXPORT_SYMBOL(debug_register_view);
1083
1084/*
1085 * debug_unregister_view:
1086 */
1087int debug_unregister_view(debug_info_t *id, struct debug_view *view)
1088{
1089 struct dentry *dentry = NULL;
1090 unsigned long flags;
1091 int i, rc = 0;
1092
1093 if (!id)
1094 goto out;
1095 spin_lock_irqsave(&id->lock, flags);
1096 for (i = 0; i < DEBUG_MAX_VIEWS; i++) {
1097 if (id->views[i] == view)
1098 break;
1099 }
1100 if (i == DEBUG_MAX_VIEWS) {
1101 rc = -1;
1102 } else {
1103 dentry = id->debugfs_entries[i];
1104 id->views[i] = NULL;
1105 id->debugfs_entries[i] = NULL;
1106 }
1107 spin_unlock_irqrestore(&id->lock, flags);
1108 debugfs_remove(dentry);
1109out:
1110 return rc;
1111}
1112EXPORT_SYMBOL(debug_unregister_view);
1113
1114static inline char *debug_get_user_string(const char __user *user_buf,
1115 size_t user_len)
1116{
1117 char *buffer;
1118
1119 buffer = kmalloc(user_len + 1, GFP_KERNEL);
1120 if (!buffer)
1121 return ERR_PTR(-ENOMEM);
1122 if (copy_from_user(buffer, user_buf, user_len) != 0) {
1123 kfree(buffer);
1124 return ERR_PTR(-EFAULT);
1125 }
1126 /* got the string, now strip linefeed. */
1127 if (buffer[user_len - 1] == '\n')
1128 buffer[user_len - 1] = 0;
1129 else
1130 buffer[user_len] = 0;
1131 return buffer;
1132}
1133
1134static inline int debug_get_uint(char *buf)
1135{
1136 int rc;
1137
1138 buf = skip_spaces(buf);
1139 rc = simple_strtoul(buf, &buf, 10);
1140 if (*buf)
1141 rc = -EINVAL;
1142 return rc;
1143}
1144
1145/*
1146 * functions for debug-views
1147 ***********************************
1148*/
1149
1150/*
1151 * prints out actual debug level
1152 */
1153
1154static int debug_prolog_pages_fn(debug_info_t *id, struct debug_view *view,
1155 char *out_buf)
1156{
1157 return sprintf(out_buf, "%i\n", id->pages_per_area);
1158}
1159
1160/*
1161 * reads new size (number of pages per debug area)
1162 */
1163
1164static int debug_input_pages_fn(debug_info_t *id, struct debug_view *view,
1165 struct file *file, const char __user *user_buf,
1166 size_t user_len, loff_t *offset)
1167{
1168 int rc, new_pages;
1169 char *str;
1170
1171 if (user_len > 0x10000)
1172 user_len = 0x10000;
1173 if (*offset != 0) {
1174 rc = -EPIPE;
1175 goto out;
1176 }
1177 str = debug_get_user_string(user_buf, user_len);
1178 if (IS_ERR(str)) {
1179 rc = PTR_ERR(str);
1180 goto out;
1181 }
1182 new_pages = debug_get_uint(str);
1183 if (new_pages < 0) {
1184 rc = -EINVAL;
1185 goto free_str;
1186 }
1187 rc = debug_set_size(id, id->nr_areas, new_pages);
1188 if (rc != 0) {
1189 rc = -EINVAL;
1190 goto free_str;
1191 }
1192 rc = user_len;
1193free_str:
1194 kfree(str);
1195out:
1196 *offset += user_len;
1197 return rc; /* number of input characters */
1198}
1199
1200/*
1201 * prints out actual debug level
1202 */
1203static int debug_prolog_level_fn(debug_info_t *id, struct debug_view *view,
1204 char *out_buf)
1205{
1206 int rc = 0;
1207
1208 if (id->level == DEBUG_OFF_LEVEL)
1209 rc = sprintf(out_buf, "-\n");
1210 else
1211 rc = sprintf(out_buf, "%i\n", id->level);
1212 return rc;
1213}
1214
1215/*
1216 * reads new debug level
1217 */
1218static int debug_input_level_fn(debug_info_t *id, struct debug_view *view,
1219 struct file *file, const char __user *user_buf,
1220 size_t user_len, loff_t *offset)
1221{
1222 int rc, new_level;
1223 char *str;
1224
1225 if (user_len > 0x10000)
1226 user_len = 0x10000;
1227 if (*offset != 0) {
1228 rc = -EPIPE;
1229 goto out;
1230 }
1231 str = debug_get_user_string(user_buf, user_len);
1232 if (IS_ERR(str)) {
1233 rc = PTR_ERR(str);
1234 goto out;
1235 }
1236 if (str[0] == '-') {
1237 debug_set_level(id, DEBUG_OFF_LEVEL);
1238 rc = user_len;
1239 goto free_str;
1240 } else {
1241 new_level = debug_get_uint(str);
1242 }
1243 if (new_level < 0) {
1244 pr_warn("%s is not a valid level for a debug feature\n", str);
1245 rc = -EINVAL;
1246 } else {
1247 debug_set_level(id, new_level);
1248 rc = user_len;
1249 }
1250free_str:
1251 kfree(str);
1252out:
1253 *offset += user_len;
1254 return rc; /* number of input characters */
1255}
1256
1257/*
1258 * flushes debug areas
1259 */
1260static void debug_flush(debug_info_t *id, int area)
1261{
1262 unsigned long flags;
1263 int i, j;
1264
1265 if (!id || !id->areas)
1266 return;
1267 spin_lock_irqsave(&id->lock, flags);
1268 if (area == DEBUG_FLUSH_ALL) {
1269 id->active_area = 0;
1270 memset(id->active_entries, 0, id->nr_areas * sizeof(int));
1271 for (i = 0; i < id->nr_areas; i++) {
1272 id->active_pages[i] = 0;
1273 for (j = 0; j < id->pages_per_area; j++)
1274 memset(id->areas[i][j], 0, PAGE_SIZE);
1275 }
1276 } else if (area >= 0 && area < id->nr_areas) {
1277 id->active_entries[area] = 0;
1278 id->active_pages[area] = 0;
1279 for (i = 0; i < id->pages_per_area; i++)
1280 memset(id->areas[area][i], 0, PAGE_SIZE);
1281 }
1282 spin_unlock_irqrestore(&id->lock, flags);
1283}
1284
1285/*
1286 * view function: flushes debug areas
1287 */
1288static int debug_input_flush_fn(debug_info_t *id, struct debug_view *view,
1289 struct file *file, const char __user *user_buf,
1290 size_t user_len, loff_t *offset)
1291{
1292 char input_buf[1];
1293 int rc = user_len;
1294
1295 if (user_len > 0x10000)
1296 user_len = 0x10000;
1297 if (*offset != 0) {
1298 rc = -EPIPE;
1299 goto out;
1300 }
1301 if (copy_from_user(input_buf, user_buf, 1)) {
1302 rc = -EFAULT;
1303 goto out;
1304 }
1305 if (input_buf[0] == '-') {
1306 debug_flush(id, DEBUG_FLUSH_ALL);
1307 goto out;
1308 }
1309 if (isdigit(input_buf[0])) {
1310 int area = ((int) input_buf[0] - (int) '0');
1311
1312 debug_flush(id, area);
1313 goto out;
1314 }
1315
1316 pr_info("Flushing debug data failed because %c is not a valid "
1317 "area\n", input_buf[0]);
1318
1319out:
1320 *offset += user_len;
1321 return rc; /* number of input characters */
1322}
1323
1324/*
1325 * prints debug header in raw format
1326 */
1327static int debug_raw_header_fn(debug_info_t *id, struct debug_view *view,
1328 int area, debug_entry_t *entry, char *out_buf)
1329{
1330 int rc;
1331
1332 rc = sizeof(debug_entry_t);
1333 memcpy(out_buf, entry, sizeof(debug_entry_t));
1334 return rc;
1335}
1336
1337/*
1338 * prints debug data in raw format
1339 */
1340static int debug_raw_format_fn(debug_info_t *id, struct debug_view *view,
1341 char *out_buf, const char *in_buf)
1342{
1343 int rc;
1344
1345 rc = id->buf_size;
1346 memcpy(out_buf, in_buf, id->buf_size);
1347 return rc;
1348}
1349
1350/*
1351 * prints debug data in hex/ascii format
1352 */
1353static int debug_hex_ascii_format_fn(debug_info_t *id, struct debug_view *view,
1354 char *out_buf, const char *in_buf)
1355{
1356 int i, rc = 0;
1357
1358 for (i = 0; i < id->buf_size; i++)
1359 rc += sprintf(out_buf + rc, "%02x ", ((unsigned char *) in_buf)[i]);
1360 rc += sprintf(out_buf + rc, "| ");
1361 for (i = 0; i < id->buf_size; i++) {
1362 unsigned char c = in_buf[i];
1363
1364 if (isascii(c) && isprint(c))
1365 rc += sprintf(out_buf + rc, "%c", c);
1366 else
1367 rc += sprintf(out_buf + rc, ".");
1368 }
1369 rc += sprintf(out_buf + rc, "\n");
1370 return rc;
1371}
1372
1373/*
1374 * prints header for debug entry
1375 */
1376int debug_dflt_header_fn(debug_info_t *id, struct debug_view *view,
1377 int area, debug_entry_t *entry, char *out_buf)
1378{
1379 unsigned long base, sec, usec;
1380 unsigned long caller;
1381 unsigned int level;
1382 char *except_str;
1383 int rc = 0;
1384
1385 level = entry->id.fields.level;
1386 base = (*(unsigned long *) &tod_clock_base[0]) >> 4;
1387 sec = (entry->id.stck >> 12) + base - (TOD_UNIX_EPOCH >> 12);
1388 usec = do_div(sec, USEC_PER_SEC);
1389
1390 if (entry->id.fields.exception)
1391 except_str = "*";
1392 else
1393 except_str = "-";
1394 caller = (unsigned long) entry->caller;
1395 rc += sprintf(out_buf, "%02i %011ld:%06lu %1u %1s %02i %pK ",
1396 area, sec, usec, level, except_str,
1397 entry->id.fields.cpuid, (void *)caller);
1398 return rc;
1399}
1400EXPORT_SYMBOL(debug_dflt_header_fn);
1401
1402/*
1403 * prints debug data sprintf-formated:
1404 * debug_sprinf_event/exception calls must be used together with this view
1405 */
1406
1407#define DEBUG_SPRINTF_MAX_ARGS 10
1408
1409static int debug_sprintf_format_fn(debug_info_t *id, struct debug_view *view,
1410 char *out_buf, debug_sprintf_entry_t *curr_event)
1411{
1412 int num_longs, num_used_args = 0, i, rc = 0;
1413 int index[DEBUG_SPRINTF_MAX_ARGS];
1414
1415 /* count of longs fit into one entry */
1416 num_longs = id->buf_size / sizeof(long);
1417
1418 if (num_longs < 1)
1419 goto out; /* bufsize of entry too small */
1420 if (num_longs == 1) {
1421 /* no args, we use only the string */
1422 strcpy(out_buf, curr_event->string);
1423 rc = strlen(curr_event->string);
1424 goto out;
1425 }
1426
1427 /* number of arguments used for sprintf (without the format string) */
1428 num_used_args = min(DEBUG_SPRINTF_MAX_ARGS, (num_longs - 1));
1429
1430 memset(index, 0, DEBUG_SPRINTF_MAX_ARGS * sizeof(int));
1431
1432 for (i = 0; i < num_used_args; i++)
1433 index[i] = i;
1434
1435 rc = sprintf(out_buf, curr_event->string, curr_event->args[index[0]],
1436 curr_event->args[index[1]], curr_event->args[index[2]],
1437 curr_event->args[index[3]], curr_event->args[index[4]],
1438 curr_event->args[index[5]], curr_event->args[index[6]],
1439 curr_event->args[index[7]], curr_event->args[index[8]],
1440 curr_event->args[index[9]]);
1441out:
1442 return rc;
1443}
1444
1445/*
1446 * debug_init:
1447 * - is called exactly once to initialize the debug feature
1448 */
1449static int __init debug_init(void)
1450{
1451 s390dbf_sysctl_header = register_sysctl_table(s390dbf_dir_table);
1452 mutex_lock(&debug_mutex);
1453 debug_debugfs_root_entry = debugfs_create_dir(DEBUG_DIR_ROOT, NULL);
1454 initialized = 1;
1455 mutex_unlock(&debug_mutex);
1456 return 0;
1457}
1458postcore_initcall(debug_init);